This chapter is dedicated to the guiding concept of the book and its grounding in social theory. Technocratic internationalism, it is suggested, should be understood with the help of modernization theory, in general, and Max Weber’s account of the expert bureaucracy, in particular. Weber’s theory of universal rationalization is associated with the advance of explicit rules, formal procedure, technical expertise, and disciplined communication in governing modern societies. These elements come together in Weber’s concept of the modern expert bureaucracy that is technically superior to pre-modern forms of public administration. The historical evidence shows that Weber feared bureaucratic modernization, because it eroded individual liberty and creativity. These internal tensions and ambiguities of technocratic modernity are a recurring theme in this book. The second part of the chapter explores the construction of an intellectual tradition. It clarifies how technocratic internationalism is a concept introduced ex post for analytical purposes: a heuristic tool that renders a strand of international theory visible, simply by giving it a name and suggesting that writings from different historical periods have enough traits in common to form such a tradition. The chapter also elaborates on the selection of authors and writings included in this volume.